An article published today in Journal of Biology shows that the phosphatidylserine receptor, previously thought to be critical for the recognition and engulfment of dying cells, is not in fact necessary for these processes at all. Instead, the researchers found that the receptor is involved in the differentiation of a wide range of tissues during embryogenesis.
When cells undergo programmed cell death, they spill their normally hidden contents and their neighbours can thus recognise them as sick or dead and dispose of them accordingly. A particular recognition signal is provided by the normally internal phospholipid, phosphatidylserine, which dying cells expose on their surface.
Yet, Dr Andreas Lengeling and his colleagues from the German Research Center for Biotechnology found that the same patterns of cell death occurred during development in both wild-type (control) mice and mice lacking the phosphatidylserine receptor (Ptdsr). In addition, macrophages without Ptdsr, when studied in vitro, were just as efficient at ingesting dying cells as wild-type macrophages.
This evidence contradicts previous studies*, which concluded that mice with no Ptdsr are deficient at clearing up apoptosing cells, and consequently that the receptor is essential to this process. It is not yet clear precisely how the earlier studies led to such different conclusions about the role for the receptor, but one factor may be differences in the genetic background of the knockout mice that were studied by the various groups. In addition, Dr. Lengeling and his colleagues made more detailed studies in a wider range of tissue types than other researchers had previously carried out.
Dr Lengelings findings open up the possibility that another, as yet unknown, receptor exists that recognises phosphatidylserine on dying cells and promotes their ingestion. Alternatively, the engulfment of apoptosing cells may be mediated via phosphatidylserine-binding proteins and their receptors.
As dead and dying cells spill their otherwise internal contents, their rapid engulfment by neighbouring cells or professional phagocytes is needed to prevent the induction of autoimmune or inflammatory disorders. An accurate understanding of the molecular mechanisms behind the clearance of cell "corpses", and consequently what might go wrong with this process, could lead to the development of treatments for these disorders - and is important if money and time are not to be wasted creating ineffective remedies.
The experiments performed by Dr Lengeling and his team showed that rather than recognising apoptotic cells, Ptdsr may well be involved in stimulating macrophages to release pro-inflammatory cytokines. Most importantly, however, Ptdsr appears to promote the differentiation of lung, kidney, intestine and other organs. Mice with no Ptdsr died either prior to or shortly after birth, were growth retarded, and experienced delayed organ development. Some knockout mice had severely disturbed eye development.
At last, butterflies get a bigger, better evolutionary tree
16.02.2018 | Florida Museum of Natural History
New treatment strategies for chronic kidney disease from the animal kingdom
16.02.2018 | Veterinärmedizinische Universität Wien
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).
Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
16.02.2018 | Information Technology
16.02.2018 | Health and Medicine
16.02.2018 | Physics and Astronomy